| 摘要 |
PROBLEM TO BE SOLVED: To provide a fixing device that can prevent accidents, such as giving serious damages to the fixing device itself, by properly detecting output failures of non-contact temperature sensors and of contact temperature sensors. SOLUTION: The fixing device has a heat roll 1 for fixing a toner on paper by means of heating; a heater lamp 2 for giving heat to the heat roll 1; heater drive circuits 8, 13 for feeding power to the heater lamp 2; the non-contact temperature sensors 5, 11 for detecting a temperature on the surface of the heat roll; the contact temperature sensors 4, 10 for detecting the temperature on the surface of the heat roll, by making it come into contact therewith; and a control circuit 9 for sending a signal, to execute or stop power feeding to the heater drive circuits 8, 13, on the basis of temperature information from the non-contact temperature sensors 5, 11. When the control temperature of the heat roll 1 is switched into a plurality of values by the kinds of paper, or the like, the fixing device switches a temperature for checking the temperature abnormality of the heat roll surface or the abnormality due to the fouling of the non-contact and contact temperature sensors 5, 11, 4, 10. COPYRIGHT: (C)2008,JPO&INPIT
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